Stents may be inserted into an anatomical vessel or duct for various purposes. Stents may maintain or restore patency in a formerly blocked or constricted passageway, for example, following a balloon angioplasty procedure. Other stents may be used for different procedures, for example, stents placed in or about a graft have been used to hold the graft in an open configuration to treat an aneurysm. Additionally, stents coupled to one or both ends of a graft may extend proximally or distally away from the graft to engage a healthy portion of a vessel wall away from a diseased portion of an aneurysm to provide endovascular graft fixation.
The material used to manufacture the stent must be capable of enduring varying amounts of stress and strain once formed into a stent. Further, the stent should have the capability of going from an expanded formation into a compressed formation when the stent is placed within a delivery device. The stent must also be capable of enduring constant cycling in a corrosive atmosphere with no fatigue or weakening. One particularly useful type of stent is a z-stent. With z-stents, a given radius is required at the apex of adjoining struts of the stent that will accommodate the range of elastic deformation necessary to expand from a low profile when compressed for introduction into the deployed configuration.
Stents manufactured with a smaller radius to lower the overall profile of the stent may result in a shorter fatigue life. In addition, a stent made of a smaller diameter wire to lower the profile of the stent may have less radial force upon deployment and a shorter fatigue life. Stents having shorter strut-lengths to increase the amount of radial force may increase in the number of struts, which could lead to the stent having a higher profile.